One of the attractions of a humanist wedding is that the couple is free to say in their own words why they're here, where they're going and what they're promising, and it's probably the main reason that they've rocketed in popularity since the registrar general of Scotland made them legal in June 2005. Although the institution of marriage has been in decline since the end of the second world war, humanist ceremonies have bucked the trend and last year humanist weddings quietly overtook Catholic ones to become the third most popular form of the ceremony in Scotland.

There were 23,000 marriages in Scotland between January and September 2010. Fifty eight per cent were either civil or humanist. Only 42% were religious.

Last year I married 100 couples, of whom about a quarter had travelled to Scotland because it's the only part of the UK where humanist marriage has legal status. Amanda and Dave came up from Surrey. Humanists don't presume to tell other people what to think or how to live, so when we met to talk about their ceremony, I told them it wasn't for me to tell them what marriage meant. Instead I asked them to think about what it meant to them and then tell us. I helped them write their ceremony, and in return, they invited some friends and family members to help me deliver it.

A few months later, we all gathered at Melville Castle, where Mark, the best man, told us Dave's story about finding Amanda on eBay, Amanda's sister Julie recounted the tale of their first date on a wet and windy Brighton beach, their friend Sarah gave us her take on what makes them click, and Alexia and Sandra took turns in reading from The Prophet by Kahlil Gibran. Then, in the presence of their family and friends, Amanda and Dave told us why they love one another, and they spoke the promises to one another that they'd written in their own words. There wasn't a dry eye in the keep.